Anodic-Oxidation Products of 2',5'-Dimethoxyacetanilide Derivatives, and Their Application to the Synthesis of Aminoanthraquinones

Abstract

Anodic oxidation of simple 2′,5′-dimethoxyacetanilides proceeds under mildly basic conditions to afford either monomeric or dimeric quinone bisacetals, depending on the structure of the substrate. Similarly, the oxidation of linked derivatives of 2′,5′-dimethoxyacetanilides is shown to exhibit a comparable sensitivity, with non-alkylated amides being efficiently converted into bis(quinone bisacetals). The regiospecificity of acetal hydrolysis for both simple and linked quinone bisacetals is shown to be dependent upon the nature of the N-acyl group. The annelation of these hydrolysis products with the anion of 3-cyanophthalide to yield (acylamino)anthraquinones is also reported.